Gyroscopes can help you fly drones and track your activity. They can also kick your ass to next Thursday and back. In time for a repeat performance tomorrow. The DynaMax Gyroscopic Core Trainer employs this spherical feat of physics as the control center of its hand-held device intended to exact upon users an intense upper body, fat burning, and core training workout.

Get the Core Trainer spinning lawnmower-style, with the pull of its handle's power cord, and then "hold on for the gyroscopic ride of your life!" Granted, that's a quote from maker DFX Sports & Fitness, but I wouldn't call it an overstatement. I actually tried out this equipment at CES this year, and would argue that its central dome houses not a gyroscope but the soul of a wild beast. About 3 seconds after the DFX dude got it gyrating for me and handed it over, I felt like I had just be charged with walking an angered bull on a leash. I'm sure the scene was as poor-bastard comical to onlookers as that of this guy in a plaid shirt and backpack trying out a pair of Rocket Skates was to me.

The power of the Core Trainer's gyroscope is no joke. Though the device itself weighs only 6 pounds, its internal whirling dervish can spin at up to 8,000 RPMs, producing up to 200 pounds of resistance. And not just straight heft that exactly moves as you do. The gyroscope moves on its own schedule, both in terms of rate and direction, fluctuating based on your ability to stabilize and control it. This forces users to brace their cores at all times, and sculpts the body via variable, dynamic resistance building. To lessen the blow of its grueling physical demands, the Core Trainer also incorporates built-in LED lights that provide a visual indication of how fast the gyro is spinning. In other words, the faster you spin, the better your light show.

This DynaMax gyroscopic trainer is the top tier of DFX's line, originally designed from the US Military Special Forces. If you're not quite ready to invest the effort (and dollars) in the Core Trainer, the company also has a Pro Trainer model that achieves slightly lower resistances and RPMs, at 178 pounds and 6,000 respectively.